Thanks for your experience with Fidelity. I have accounts with ETrade and Ameritrade. Both also offer free real time quotes and Level II. However, the Ameritrade quotes have been very poor, such as lots of down time and discontinuity... ETrade I believe only allows one Level II window.
I am happy to pay for a reasonable cost to get "professional grade" data feed... Anyone?
Market Data 
Markets 
AI
